1. Field of the Invention
Embodiments of the present invention generally relate to wireless communications and, more particularly, to decoding wireless transmissions.
2. Description of the Related Art
The rapid growth in wireless communications services, such as broadband Internet access and streaming media applications, leads to an increasing demand for higher data rates. Advancements in multiplexing schemes, such as Orthogonal Frequency Division Multiplexing (OFDM) and Orthogonal Frequency Division Multiple Access (OFDMA), are important for next generation wireless communications systems. This is due to the fact that such schemes can provide many advantages including modulation efficiency, spectrum efficiency, flexibility (e.g., allowing differentiated quality of service), and strong multi-path immunity over conventional single carrier modulation schemes.
OFDM and OFDMA systems often utilize convolutional encoders at the transmitter to provide for error correction. Using a convolutional code, an m-bit string of data is transformed into n-bits, where m/n is a coding rate. Decoders, such as Viterbi decoders, are used at the receiver to decode the received encoded n-bits to recover the original m-bit sequence. This scheme often allows the original m-bit sequence to be decoded correctly, even if one or more of the encoded n-bits is not received correctly, thus resulting in reductions in bit error rate.
However, with the ever increasing reliability and performance demands of wireless services, there is an ongoing need to continuously reduce bit error rates.